If we choose to live near convergent plate boundaries, we can build buildings that can resist earthquakes, and we can evacuate areas around volcanoes when they threaten to erupt. Yes, convergent boundaries are dangerous places to live, but with preparation and watchfulness, the danger can be lessened somewhat.
Nitrification, as stated above, is formally a two-step process; in the first step ammonia is oxidized to nitrite, and in the second step nitrite is oxidized to nitrate. Different microbes are responsible for each step in the marine environment.
The purpose of nitriding is to enrich the surface layer of a work piece with nitrogen in order to increase the hardness in the surface. The process of nitriding takes advantage of the low solubility of nitrogen in the ferritic crystal structure to promote the precipitation of iron nitrides or alloy nitrides.